Just what the title says. I need to ship a couple of whole cases of MREs across the country. Does not matter how long it takes. What's the absolute dirt-cheapest way to do it? I don't have any accounts with FedEx or UPS or USPS, so I would be a cash customer. I know they always charge more for that.

"No trees were harmed in the sending of this message... however, several million electrons were greatly inconvenienced."